Heat exchange catheters with bi-directional fluid flow and their methods of manufacture and use

Abstract

Closed loop heat exchange catheters having bi-directional flow heat exchange regions and their methods of manufacture and use. The heat exchange region may be formed of expandable or non-expandable tubular conduit(s) that are configured in a series of loops or coiled configuration defining a supply flow path and a return flow path through which heat exchange medium is circulated. The individual loops of convolutions of the coiled configuration may be the same or different size. In some embodiments, the tubular conduit(s) may be passed through generally transverse bore holes formed in a catheter shaft so that the loops or convolutions of protrude from the catheter shaft.

What is claimed is: 
     
       1. A heat exchange catheter device comprising:
 an elongate body having an inflow lumen, an outflow lumen and a heat exchange region, wherein the heat exchange region comprises a tubular conduit, one end of said tubular conduit being connected to the inflow lumen and the other end of said tubular conduit being connected to the outflow lumen; 
 a first segment of the tubular conduit having loops or convolutions of a first diameter or cross-dimension, said first segment forming a fluid supply flow path through which heat exchange fluid may flow in a distal direction from the end of the tubular conduit that is connected to the inflow lumen; 
 a second segment of the tubular conduit having loops or convolutions of a second diameter or cross-dimension, said second segment forming a fluid return flow path through which heat exchange fluid may return in a proximal direction to the end of the tubular conduit that is connected to the outflow lumen; 
 wherein one of said first and second diameters or cross-dimensions is larger than the other of said first and second diameters or cross-dimensions. 
 
     
     
       2. A heat exchange catheter device according to  claim 1  wherein the fluid supply flow path has loops or convolutions which overlap or cross loops or convolutions of the fluid return flow path. 
     
     
       3. A heat exchange catheter device according to  claim 1  wherein the fluid supply flow path differs in length from the fluid return flow path. 
     
     
       4. A system comprising a heat exchange catheter according to  claim 1  in combination with apparatus for circulating heated or cooled heat exchange fluid in the inflow lumen, through the fluid supply flowpath, through the fluid return flow path and out of the outflow lumen. 
     
     
       5. A system according to  claim 4  further comprising a temperature sensor to sense a subject body temperature. 
     
     
       6. A system according to  claim 5  wherein the temperature sensor is connected to a controller, said controller being programmed to adjust the temperature or flow rate of the heat exchange fluid in response to indications of the sensed subject body temperature that the controller receives from the temperature sensor. 
     
     
       7. A system according to  claim 6  further comprising a user interface by which a user may input a target body temperature to the controller. 
     
     
       8. A heat exchange catheter device according to  claim 1  wherein the segments of tubular conduit are initially in a collapsed configuration and assume an expanded configuration when heat exchange fluid is circulated therethrough. 
     
     
       9. A heat exchange catheter device according to  claim 1  wherein the tubular conduit has a wall thickness of less than approximately 0.001 inch or another thickness sufficient to withstand and withstands pressures of up to approximately 100 psi when the heat exchange fluid is being circulated. 
     
     
       10. A heat exchange catheter device according to  claim 1  wherein the tubular conduit is laced or passed through spaced apart locations on a distal portion of the elongate body. 
     
     
       11. A heat exchange catheter device according to  claim 10  wherein the tubular conduit is laced or passed through a series of spaced-apart transverse passages formed in the distal portion of the elongate body. 
     
     
       12. A heat exchange catheter device according to  claim 1  further comprising a through lumen that extends longitudinally through the catheter device and terminates distally in a distal port. 
     
     
       13. A heat exchange catheter device according to  claim 12  wherein the through lumen is useable as a guidewire lumen to facilitate insertion of the catheter over a guidewire. 
     
     
       14. A heat exchange catheter device according to  claim 12  wherein the through lumen is useable as a delivery lumen to facilitate delivery of a therapeutic substance or device. 
     
     
       15. A heat exchange catheter device according to  claim 1  wherein loops or convolutions formed in the fluid supply flow path are not coaxial with loops or convolutions formed in the fluid return flow path. 
     
     
       16. A heat exchange catheter device according to  claim 1  wherein loops or convolutions formed in the fluid supply flow path are coaxial with loops or convolutions formed in the fluid return flow path. 
     
     
       17. A heat exchange catheter device comprising:
 a proximal catheter shaft having an inflow lumen, an outflow lumen and a distal end; 
 a heat exchanger which extends from the distal end of the catheter shaft, said heat exchanger comprising a tubular conduit, one end of said tubular conduit being connected to the inflow lumen and the other end of said tubular conduit being connected to the outflow lumen; 
 a first segment of the tubular conduit having loops or convolutions of a first diameter or cross-dimension, said first segment forming a fluid supply flow path through which heat exchange fluid may flow in a distal direction from the end of the tubular conduit that is connected to the inflow lumen; 
 a second segment of the tubular conduit having loops or convolutions of a second diameter or cross-dimension, said second segment forming a fluid return flow path through which heat exchange fluid may return in a proximal direction to the end of the tubular conduit that is connected to the outflow lumen; 
 wherein one of said first and second diameters or cross-dimensions differs from the other of said first and second diameters or cross-dimensions. 
 
     
     
       18. A heat exchange catheter device according to  claim 17  wherein the fluid supply flow path differs in length from the fluid return flow path. 
     
     
       19. A heat exchange catheter device according to  claim 18  wherein the fluid supply flow path is longer than the fluid return flow path. 
     
     
       20. A heat exchange catheter device according to  claim 17  wherein the fluid supply flow path has loops or convolutions which overlap or cross loops or convolutions of the fluid return flow path. 
     
     
       21. A heat exchange catheter device according to  claim 17  wherein the loops or convolutions comprise helical loops. 
     
     
       22. A heat exchange catheter device according to  claim 21  wherein helical loops of the first segment alternate with helical loops of the second segment.